Ultralife Corp

Ultralife Corporation (the "Company") is unable to file its Annual Report on Form 10-K for the fiscal year ended December 31, 2025, within the prescribed time period without unreasonable effort or expense. The Company's independent auditors require additional time for the completion of their internal documentation and review process to finalize the audit of the Company’s financial statements and internal controls over financial reporting. The Company expects to file its Form 10-K within the fifteen-day period provided under Rule 12b-25 of the Securities Exchange Act of 1934, as amended, no later than March 31, 2026. This delay in filing is not the result of any disagreements with the Company’s independent auditors on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure. Management does not anticipate any material changes to the financial information furnished with the Form 8-K filed by the Company on March 10, 2026. Attached hereto and filed as Exhibit 99.1 to this Form 12b-25 is the statement of our independent auditors as required by Rule 12b-25(c) of the Securities Exchange Act of 1934, as amended

As previously disclosed, on October 31, 2024, Ultralife Corporation (“Ultralife”) completed the acquisition of all outstanding shares of Electrochem Solutions, Inc. (“Electrochem”) from Integer Holdings Corporation (“Integer”). During the third quarter of 2025, the transition services agreement between Ultralife and Integer under which Integer maintained the books and records of Electrochem on its information systems concluded, and Electrochem transitioned to Ultralife’s systems. In connection with this transition, Ultralife requires additional time to finalize its third quarter results and to provide sufficient time for completion of the review of our third quarter results by our independent accountants without unreasonable effort or expense. The Company expects to file its Form 10-Q within the five-day period provided under Rule 12b-25 of the Securities Exchange Act of 1934, as amended, no later than November 17, 2025

As previously disclosed, on October 31, 2024, Ultralife Corporation (“Ultralife”) completed the acquisition of all outstanding shares of Electrochem Solutions, Inc. (“Electrochem”) in a cash transaction from Integer Holdings Corporation (NYSE: ITGR). Due primarily to delays resulting from our reliance on the former parent company of Electrochem to provide their financial results and supporting information under a transition services obligation as part of the stock purchase agreement, and for Ultralife to ensure the resulting purchase accounting is in compliance with U.S. Generally Accepted Accounting Principles, Ultralife requires additional time to prepare the consolidated financial statements and the accompanying notes disclosed in their Annual Report on Form 10-K and for completion of the audit by our independent accountants without unreasonable effort or expense. The Company expects to file its Form 10-K within the fifteen-day period provided under Rule 12b-25 of the Securities Exchange Act of 1934, as amended, no later than April 1, 2025